Razor-stropping machine



May l, 1923. 1,453,75l

E. D. CLARK RAZOR STROPPING MACHINE Filed dan. 5, 1921 Patente-d May l,1923.

ERNEST D. CLARK, or wonfonsirasn; MSSAGHUSETTS. .i

RAZOB-STROPPINGfiirAoEIivEl -4 AppncationmeaJanuary 5,-ie2ifsegiaifiiqiasgws. f

To all whom 'it-my'fcoaoefm; y

@Beit known thatL ERNEST D. CLARK,- a citizen: of the United States,residing at l/Vorcester, Ain the county 'ofWorcester-v and 5Commonwealth of-Massachusetts, have invvented-l a 'new and 'usefulImprovement in lRazor-Stropping aMachines, of which -1 thefollowing,1together with the accompanying drawings, is a specification.'

Myinvention relates tov yrazor stropping machines of the type in whichla blade holder is moved withrrespect to afstrop,l in order to'sharpentlie edge ofa blade carriedbythe holder. i 15 Razorstrapping'Amachines ofthis type vhave heretoforebeen constructed for moving thebladetransversely*across the face of the str-op, at the'asame time thatthe blade is moved'lon'gitudinally#along the strop. These movements have@been obtained v simultaneously V- 'by f 'various fmechanisms actuatedby the` relati`v`e movement between the machine andrthestrop; "and such'machines' havebeen successful liii-obtaining aE diagonal moveffm'ntofthe fbla'de: with respect tothe strop "in imitation 'of ithe strokeemployed when sharpening a blade hand. K.

f" Such @prior machines', howeverg'have been ffo'peto 'the' defectthat'lthey"faily to imitate the [complete moveiiient'i whiclif'isimparted to abladewh'en'it is desi-redv tof'sharpen both 'sides thereof.-l It-is "fw-ell.:knownfthatj when yitis desired *tosharpen arazor,"orany `'other cutting blade,` 'that one edge isV first drawn"diagonallyHacrossithe strop f'orstone 'and then at the end of thisstrokelthefblade fis firsts'hift'edacros's the strop and then turnedover 'before'theoth'er cutting-edge is` drawn diagonally across thestrep; butinthe same *direction in which the blade'was first drawn.

- This cyclefof movementk iis always 'repeated z*in order to'insure'`Jchat/'the flow 'ofpmet'al which occurs' along 'the cutting 'edgewil-ll* al-v ways be iii-one fdirectionl Thus,fin`sharpen Ving aknifefthis';flowj'of metal is always in Vthedirection ofth'epoint yvInall'prior razor*stroppingfmachines, the

" movements .have been such that' the metaly is 'first drawn' in -"one"ydirection on one side lof ythe, blade 'and then'in the loppositedirection on the-'i other'Y side "off the Vbla'degthus departing fromthe usual methodo-fstropping,.and

necessarilyfailing to obtainy the b'e'st results; "This" is dueto the'fact 'that inprior' machines '`the'blade' zalways follows thesarnefdiagonal path;l across the strop,i l y rections. y ...l i. Y ,1 l 1 iBymy' invention propose tapfpwidyja a novel form1 'ofjrazor 'stropp'ingmachinefyin whiclr the blade -isiiirst drawn diafggolially,"lcrosl'slthe L solthatfthe metal: is drawn g in algivenydirection;andthemupon.reversving the blade it isffsof s'hifted ,withrespctflo .the stropthat themetal isst'illvdrawn inthe same direction fvupon` the'y returna` diagonal lmovement rof theY blade with respect thei@ strop. 11n this way it possible to'obtainy a complete cycle of-movemenuclosely Y approxiinatingfthatlwhichpoccurs when a bladeffis'sharpened 'by hand. Theseandother l advanstageousr features -Vofinvention -wjill herein- .f

`after. more fully appeanfreference being@- had to Sarthe aecomp anyingVjdrawings-fin which# 'Egure leise a View fn-ndalfvatiwvi lmach-ineembodying.- myinvention'A the lend `plate being removed. 'i l 'Figure 2is va'flongitlidinalY sectional walongithe -line 2-.f2, Eig. `l.l K

'view v niguna-isa yi'ewsimiiar to Eiga; Owl.

ing'fthefposition *ofthe parts-occupiedjwhen .the machineis;movedifingthempposite direc-L35.

' tionl froml that "shown 4in Fig. V1.v g j l Figure L)fist alongitudinal VAsectional. View 'along-the 1in@ 44=- 3 Fiese.

`Figures 5 to 85inclusive;are'diagranimatic views showing nthef'movementsf --of ffthe; blade fr "holder @as fthe m'acl'iineAis-'moved--backfand forthwith relation tothefst'op. f

v'r Similar reference.' letters freferf lto "similar "parts in "thediiierent figures. t

@referring t@ riga-1; anagagithaiathihe ,comprises a frame lV withimVwhich are -jour,-

I isplrovided'at' itsends with openings? 5 `:for f receiving the-:stropk6 l' whichtpasses".v over the rollers 2 and 4 and,underl the roller,.='f\'1?he l holder' shaft 1'1"' isfjournallednmthe frafxii. 1A

immediately aboveand parallelft'lthe worm shaft Sgam@ isH connectedteeth-@shaft of the roller 4 by fmeans of A"cran-lisVA"lQlfl-lffjoinedby a linkl. 'A'iblade" liolderi-l'ffis slidably keyedvon the shaft 11 and is provided with a radially extending pin 16 thatis adapted to engage in threads 17 provided on the left hand portion oftheY worm shaft 8, as shown in Fig. 2. The blade holder 15 may be of anysuitable form to receive aA blade 18.

When the frame 1 is moved upon the strop 6 in the direction indicated bythe arrow in Fig. 1, the roller 4 is rotated in a clockwise direction,and the shaft 11 is rotated in the same direction to cause the blade 18to engage the strop 6. This samemovement of the frame 1 also causes theroller 3 to be rotated and thereby drive the worm shaft 8 in thedirection indicated by the arrow, through the gears 9 and 10. As the pin16 is in engagement with the thread 17 on the' shaft 8, the blade holder15 will be moved from left to right, as indicated, as the frame 1 ismoved upon the strop 6 in a direction away from the user. As the bladeholder 115 is moved transversely it compresses a spring 19 surroundingthe shaft 11, for a purpose to be hereinafter described. The movement ofthe blade holder 15 as the frame 1 lis .moved the full length of itsstroke away from the user is indicated diagrammatically in Fig. 5, thespring 19 being shown as fully compressed at the vend of this stroke. vf

The frame 1 having reached the end of its stroke away from the user, thehandle is then pulled in the opposite direction as indicated in Fig. 3.When this movement begins, the roller 4 is turned in a counterclockwisedirection, as indicated, which causes the shaft 11 to be turned in thesame direction to lift the blade 18 from the right hand portion ofthestrop 6, and to turn it over into engagement with the strop 6 on theopposite side of the shaft 11. As the blade holder 15 is turned over,the pin 16 is moved out of engagement with the threads 17 so thatv thecompressed spring` 19 is free to shift the blade holder 15 back to itsoriginal position, as indicated by the arrow in Fig.l 6.

This shifting movement occurs almost instantaneously and before theblade holder 15 has been completely lturned fover by .the operation ofthe cranks 12 and 13 and the llink 14. As the blade holder 15 returns toits original position, a pin 2O located'diametrically opposite to thepin 16 at the other end of the holder engages threads 21, provided atthe right hand end of the shaft 8.

vThe threads 21 are ofv opposite pitch with respect` to the threads 17which were previously engaged by the pin 16. The position of the bladeholder 15 at the end of the shifting movement is shown diagrammati-`cally inl Fig. 7.

As the frame 1 is pulled in the direction of the user, as indicated bythe arrow in Fig. 3, the blade 18 is held in engagement with the lefthand portion of the strop by the tendency for the shaft 11 to be turnedby the roller 4,1and at the same time, the shaft 8 is rotated in theopposite direction from that in which it was rotated before, asindicated by the arrow in Fig. 4. This rotation of the shaft 8 causesthe blade holder 15 to again be shifted from left to rightas the frame 1is pulled toward the user. rI` his is due to the fact that the threads21 have a pitch opposite to the threads 17 and consequently the reversalof rotation of the shaft 8 causes shifting movement of the blade holder15 in the same direction as before. The path of movement of the bladeholder 15 as the frame 1 is moved from one end of its stroke toward theuser, to the other, is indicated diagrammatically in Fig. 7, the spring19 being shown as compressed at the end of this stroke. viously theblade holder 15 will again be shifted from right to left by the spring1b as soon as the frame 1 is started on its return stroke away from theuser.

From the foregoing, it is obvious that the' diagrammatically in Figs. 5to 8, inclusive,

from which it appears that the blade is always moved diagonally acrossthe strop 6 from left to right, as indicated by dotted -lines in thediagrams. Consequently the metal is always kdrawn in the same directionas rst one sideof the blade and then the other is presented to thestrop, by the operation of the shifting device. It is obvious that theabove described cycle of movements closely approximates the movementimparted to a blade that is being stropped by hand, and inview of thefact that the movement of the blade in my machine is always uniform, itis believed that even better results can be obtained by the use of mymachine than 'by'r hand stropping, l

While `I am aware that various machines have heretofore been employedfo-r obtaining a diagonal movement of the blade across the strop, it isbelieved that my improved machine is the first to duplicate the actualmovements of hand stropping, whereby the metal along the Cutting edge ofthe blade is always drawn in the same direction. While I have shown aspecific arrangement of instrumentalities for. obtaining the above de-`for imparting transverse movement to said blade holder always iny thesame direction across the strop as said holder is moved back and forthin engagement with the strop, whereby resulting diagonal movements ofsaid holder on the strop are in different paths.

2. In a razor stropping machine, the combination with a strop, and ablade holder longitudinally movable thereon, of means for impartingtransverse movement to said blade holder as it is moved back and forthon the strop, and further means for shifting the blade holder at the endof each longitudinal movement in a given direction across the strop,whereby resulting diagonal movements of said holder across the strop arealways in the same direction.

.8. In a razor stropping machine, the combination with a strop and ablade holder longitudinally movable thereon, of means for impartingtransverse movement to said blade holder as it is moved back and forthon the strop, and further means for simultaneously shifting said holderfrom one side of said strap to the other and turning over said bladeholder at the end'of each longitudinal movement across the strop.

4. In a razor stropping machine, the combination with a strop, a bladeholder movl.

able on said strop, and a rotatable shaft lprovided with threads ofopposite Pitch for kimparting transverse movement t0 said strop as thelatter is moved longitudinally thereon, of means for shifting the bladeholder bodily across the strop and turning itrover at the end `of eachlongitudinal movement thereon to bring said projections into engagementwith firstv the right hand and then the left hand threads on said shaft.

ERNEST D. CLARK.

